Not sure there is a generic ramp time for all SaaS teams. A lot of variables go into it, including market, industry, client demographics, lead sources, individual networks etc.
In general if you have a known process, defined client demo and aren't in a regulated market or not in an enterprise sales price range then I'd target a new sales team member being productive in the first 60-90 days depending on the complexity of the product, their network etc.
If you are in a regulated market, or the price point exceeds common purchasing managers limits than you are talking about a totally different scenario.
Those are just some really high level generic points, a lot goes into setting up a repeatable sales cycle and building the team.
